Conventionally, techniques have been known that efficiently determine a cylinder at the time of starting an internal-combustion engine. For example, Patent Literature 1 discloses a technology including: monitoring a crank angle position even during stoppage of an internal-combustion engine; calculating, based on the result, a crank angle at the time of starting the internal-combustion engine; and determining a cylinder of which a fuel injection is performed. In addition, Patent Literature 1 discloses a technique including: a first determination unit which determines a cylinder based on information regarding a crank angle position at the time of stopping an internal-combustion engine; and a second determination unit which determines a cylinder by using a combination of different Hi/Low logic signals of a cam angle sensor (corresponding to a “TDC sensor” as described herein), whereby a fuel injection is controlled at the time of starting the internal-combustion engine. Then, when a mismatch occurs between the results of the cylinder determined by the first determination unit and the cylinder determined by the second determination unit and fuel has already been injected based on the cylinder determination by the first determination unit, an amount of subsequent fuel injection of the cylinder is compensated by subtraction.